CONSTRUCTING ENVIRONMENTS Log Book Final Submission Semester 1 2014
Jackson Wylie - 638578
WEEK 1 Block Tower (Compression) This week we were set the task of building the tallest block tower possible with a limited amount of blocks. IDEA 1: Square Stack This simple design was simply too inefficient as to do 2 levels it required 14 blocks and only covered the surface area of 8 blocks, this would become very unstable as it became taller.
Figures 1,2,3. Block Stacking Ideas
Smaller Circular Stack/Weave We modified the first larger circular weave tower to allow it to achieve greater heights by reducing the circumference of the tower by 3 blocks. This did increase the risk of the tower collapsing however it was still a relatively sturdy structure due to the interweaving layers of blocks and the even load distribution (as seen in the cross section).
DESIGN 2: Large Circular Stack/Weave Inspired by the weeks lecture on the strength of circular structures as well as Ching’s (2008) reading which stated that a tube structure was an effective way of building lateral force resistant tall buildings our next design involved arranging the blocks in a circular shape consisting of 10 blocks in each layer. As evident in the below diagram the blocks on the separate layers were intentionally placed so that they would sit on two of the below blocks, adding a greater strength to the overall tower structure as it distributed the load more evenly throughout the structure and also allowing the tower to use less blocks. KEY: Cross Sections Red=Layer 1 Black=Layer 2
Lecture Sketches inspirations of design
Figures 4,5. Cylinder Load Bearing Sketches
WEEK 1 Load Diagram With each brick of each layer resting its weight upon two bricks from the layer below an overall load is being distributed across two separate bodies rather than one and therefore increasing its resistance to horizontal forces such as wind. Figure 6. Load Illustration of Brick Layers
Process & Thought According to the reading from Francis Ching (2008) towers are most effective at withstanding lateral forces if they are arranged symmetrically and this notion or law was one of the reasons that we decided to use a cylindrical/column shaped tower as it relatively easy to maintain a basic level of symmetry which will assist keeping the centre of gravity in the middle of the structure. The tower that we ended up constructing had a base consisting of 8 blocks however we gradually reduced the amount of blocks as it got taller to not only use them more efficiently but also to ensure that we were able to maintain the centre of gravity in the middle of the structure, the top layers consisted of only 5 blocks. Originally it was not the plan to reduce the amount of bricks in each layer however as we were struggling to achieve our desirable height we had to find ways to use the bricks more efficiently. Reflection On reflection, we may have not actually needed to use so many bricks in the bottom layers and this could have potentially gained us an extra 30cm in height however it would have been much more difficult to maintain the centre of gravity in the middle of the structure if we had used less bricks as the tower would have a smaller circumference. Also it was evident in the Week 1 Lecture activity that a shorter circle with a larger circumference was much more capable of supporting the brick than a smaller circle/ column with a reduced circumference. Figure 7. Block Tower
WEEK 2 STRUCTURAL LOADS AND FORCES Balsa Tower (Frame) Week 2’s task involved building the tallest tower we could possibly build out of a limited amount of thin 30cm lengths of balsa wood. Once complete the tower was to be put under some strength tests to see if it could withstand weight exerted upon it and horizontal pressure such as wind that could threaten to topple it over.
Original Design: -used too much balsa -therefore not tall enough
Adapted Design: -efficient use of balsa -taller -but much less stable - therefore weaker
Frame For our tower frame we were forced to compromise between strength and height which resulted in our idea to have only three vertical balsa lengths which were joined by horizontal beams that created a sort of triangular prism. Due to the lack of balsa provided the top segment of our tower was a triangular pyramid shape. Joints For this tower we aimed to create rigid fixed joints as we wanted to minimise the movement of our tower frame (Studio Quiz 2013). We uses tap with two small pins going through the overlapping balsa sticks.
Figure 8,9. Balsa Design Sketches
Figures 10-14 Balsa Frame Photographs, Jackson Wylie 2014
WEEK 2
E-Learning & Readings
Adjustments In attempt to improve the lateral stability of our tower frame we added some knee bracing (Ching 2008). This was not actually very effective due to the long lengths of unsupported vertical balsa lengths, on reflection k-bracing or cross bracing would have been much more effective in adding lateral stability to our tower (Ching 2008) or even adding more horizontal beams (triangles)
Structural Systems & Joints
Figures 15, 16, 17 Balsa Frame Photographs, Jackson Wylie 2014
Strength Test & Reflection In the strength test our fears were confirmed that our balsa frame did not have enough horizontal beams nor sufficient bracing to strengthen the vertical balsa lengths of the frame. The bottom half of the frame that had horizontal beams at closer vertical intervals stayed a lot more straight than the top half of our tower that had very few horizontal beams and bent quite dramatically when tested as seen in Figures 7&8. The joints of our tower were actually stronger than I had predicted as some of the longer vertical balsa lengths gave way before the joints did.
Figure 18. Structural Systems & Joints
ESD Systems
Figure 19. ESD Strategies Mindmap
WEEK 3 FOOTINGS & FOUNDATIONS E-Learning & Readings
Footings
Pad Footing: a.k.a Isolated footings, help to spread a point load over a wider area of ground Strip Footing: Used when loads from a wall or a series of columns is spread in a linear manner. Raft Foundation: Type of foundation that provides increased stability by joining the individual strips together as a single mat.
Structural Elements: The elements from which a structure is made or assembled have, in engineering or building terms, specific names which are used for convenience. Eg. Strut, Tie, Beam, Slab/Plate & Panels
Mass
Figure 20. Structural Elements
Typically very good under compression but very poor under tension Figure 21. Mass
Masonry
Masonry refers to building with units of various natural or artificial products, that are grouped/stacked together
Deep Foundations
Figure 23. Footing
End Bearing Piles: extend the foundations down to rock or soil that will provide support for the building loads Friction Piles: rely on the resistance of the surrounding earth to support the structure
Figure 24. Deep Foundation
Figure 20-24. Week 3 E-learning Sketches Figure 22. Masonry
WEEK 3 MELBOURNE UNI BUILDING TOUR
Figure 25-29. Melbourne University Construction Tour Photographs
WEEK 3
Figure 30-34. Melbourne University Construction Tour Photographs
WEEK 4 FLOOR SYSTEMS & HORIZONTAL ELEMENTS E-Learning Notes Span & Spacing
Floor Systems
Figures 35-39. Week 4 E-Learning Sketches & Mind Maps
WEEK 4 Scale, Annotations and Working Drawing Conventions Scale - ‘the ratio of the size of a model or other representation, to the actual size of the object represented.’
Scale is vital tool that helps to translate two dimensionl design drawings into into something that can be built. It enables the design to be replicated with great precision, the building should be a larger version of what has been drawn. Scale enables the builder to understand the magnitude of each aspect of the design. In terms of building constriuction plans, scales such as 1:5, 1:10 and 1:20 are often used to show fine details such as joints, window framing etc. Other scales such as 1:50, 1:100 or even 1:1000 show a more ‘zoomed out’ perspective of the building to show its context within the site or even within the broader area. Elevations of the facades of buildings are often at these larger scales. Scale is also vital in that enable the architect and builders to see the exact measurments of the different building components. Without scale, design drawings would require written annotations of measurements, however when a drawing is to scale the builder only needs to use a ruler to find the length of the drawing and multiply the measurement according to the scale ratio of the drawing.
Title & Scale ratio Compass/Orientation Consultants/References Client
Project Title Drawing No. Architect
Figure 40. Site Plan Titles Annotated
WEEK 4 Line Type & Weight LINE TYPE & WEIGHT Line type and weight plays a major role in making construction plans clear and easily interpreted. The lines with a greater weight are usually important structural elements such as columns, beams and foundations. In the case of sections, the lines of greater weight are the ones that in the foreground, where the section cuts through the building (Figure 41). As seen in in Figure 41 the lines are actually not all black, lighter shades of grey may also be incorporated to show that some structures are in the background of the image and also in the infill patterns of each material such as the bricks in figure 41. Some lines can also be dotted or fragmented, this may be for the purpose of showing something that is not actually visible, may be behind a wall. Fragmented lines can also be for reference , in figure 41 fragmented lines around the roofing details suggest that ‘zoomed in’ sections of these exist on another page.
Figure 41. Pavillion Canopy Section
WEEK 5 COLUMNS, GRIDS & WALL SYSTEMS E-Learning Notes
Figures 42,43 Week 5 E-learning: Columns & Wall Systems
WEEK 5 PAVILION MODELS The week 5 tutorial task involved making a model of the skeleton of a section of the Oval Pavilion These images to the right show the structural properties of the part of the Oval Pavillion that we had to model. The task for us in this tutorial was to attempt to build a model of this canopy structure. As evident in these images from the construction plans, this structure has very few vertical elements, it consists predominantly of many webbed trusses that cantilever off the central truss which is structurally similar to the ‘flat truss’ and ‘warren truss’ (Ching 2008). The actual canopy structural framing is steel, for our scale model we decided an appropriate material would be balsa wood, a light yet rigid material that can be easily cut and joined using either glue or pins.
central ‘warren’ truss
cantilevering webbed truss
column Figures 44,45. Canopy Structure
WEEK 5 PAVILLION MODELS Pavillion Structural Model Process
Unfortunately due to a combination of a lack of organisation and poor preparation, we had far less balsa wood than our structure required. The scale of our model was much bigger than we had anticipated. We decided to cut out some cardboard to the same dimensions of our canopy section as a template base that would make it easier to determine the overall shape and angles of our skeletal structure as each truss goes to the corners of the cardboard template.
We proceeded by first attaching the three columns, we then added beams between them which helped to form the central truss, unfortunately due to our lack of balsa wood we were unable to do the truss webbing. We then proceeded by doing the cantilevering trusses which branched off the central truss, at this point we had virtually no balsa left so these trusses were purely symbolic as they were far from complete, do to the lack of webbing and incomplete trusses the structure required us to leave the cardboard template attached to avoid it from completely falling apart.
Other Models
Afterwards we visited another class who succeeded in making the same section of canopy that we failed at. Although their structural elements werent quite to scale they had suceeded in replicating the overal skeletal structure with all of the trusses webbed. Due to their incorrenct scaling of the structural members i think that the columns would have been incapable of bearing the load of the cantilevering trsusses which were of the same width and thus weight. If the columns were made of a thicker or stonger timber then it would have been feasible that they could have suppported the load. Figures 46- 50 Canopy Structural Models
WEEK 6 SPANNING & ENCLOSING SPACE E-Learning Notes Trusses
Roof Structures
Metals
Figures 50- 52. Week 6 E- Learning: Trusses, Metals & Roof Structures
WEEK 6 Load Bearing Wall Structure This groups structural system has two distinctive layers, and the reason for this may be that the bottom layer requires strong load bearing walls that have adequate properties to endure the compressive stresses. It can be seen from this model that this is likely to be the case as there are also columns that assist in bearing the buildings load. This structural system would mostly be constructed by reinforced concrete or reinforced cinder block load bearing walls, rather than a steel frame system as the overall structure would look more like a skeletal frame system if it were a steel structure. The upper level could be made out of a lighter less structural material as it is fulfilling the purpose of enclosing space rather than supporting compressive loads.
Canopy Skeletal Structure
Load Bearing Wall
Column
Nonload bearing walls
The canopy of the Oval Central ‘warren Pavillion has a unique truss’ structure with trusses cantilevering outwards from a central ‘warren truss’ (Ching 2008) supported by 3 columns. Each of the trusses has webbing that helps to Columns distribute the compressive and also lateral loads from the outer parts of the cantileving trusses to the central struss and down through the columns and into the footings Cantilevering and slab. Truss
Figures 53-56. Oval Pavillion Structural Models
WEEK 7 E-Learning Notes
Figures 57-60. Week 7 E-Learning: Arches, Vaults, Domes & Shells
WEEK 7 DETAILING STRATEGIES E-Learning Notes
Figures 61,62. Week 7 E-Learning: Heat & Water Detailing
WEEK 8 Strategies for Openings E-LEARNING NOTES DOORS
GLASS PROPERTIES & TYPES
Figures 63-65. Week 8 E-Learning:Door Opening & Glass Infill
WEEK 8 DETAIL DRAWING & PHOTOS DETAIL DRAWING
This week’s task of drawing a detail section proved to be much more challeging than i initially expected, I initially used a single 2B greylead pencil and the outcome was that the section was unclear and difficult to interpret, in order for the image to be clear and interpretable lines must be of different weights, and care must be taken in doing different patterns that represent the different materials in the detail. What this activity revealed to me was that within many structures, especially a window frame there are various unseen components that fulfil functional purposes such as preventing the entry of water via vapour barriers and caulk and also reducing heat transmission through the internal insultation.
steel frame hollow section brick masonry wall vapour barrier
insulation
double glazed glass
framing blocks
caulk junction
steel column hollow section Figures 66. Detail Section Sketch: Window Frame
steel frame
WEEK 9 DETAILING STRATEGIES E-Learning Notes
STRESS ON STRUCTURAL MEMBERS
MOVEMENT JOINTS
Some joints are designed to enable a certain amount of movement. These materials that are used to join are often flexible and allow some level of movement as the image below shows. Some examples of movement joints include between tiles or bricks and the types of materials that are used to join include mortar, silicon, caulk etc. Figures 68-70. Week 9 E-Learning: Stresses & Movement Joints
WEEK 9 “OFF SITE” APARTMENT BLOCK STRUCTURAL SYSTEM The site that we visited during the week 9 turotial was predominantly a concrete structure. It consisted of a combination of concrete structural elements, including short reinforced concrete columns, some load bearing concrete panels, and also the horizontal structural smembers making up the flooring system including in situ concrete slabs and also structural beams. IN SITU & PRE CAST This image shows a combination of pre cast and also in situ concrete making up the structural system of this part of the apartment block. As evident in this image the vertical members are the pre cast panels or walls, due to the fact that they are load bearing it can be assumed that they may include some kind of internal steel reinforcement. The slabs making up the roof in this image is cured ‘on site’ making it ‘in situ’ concrete.
ROOF SLAB The roof slab of this building is aimed to be a rooftop garden for the residents of the building. Being a flat roof it is vital that all of the surfaces are sloping to a drainage point to avoid the build up of water as concrete can be permeable, some of the pipes coming through the slab in this image are drainage pipes. There are also openings in this roof slab that allow light to penetrate toward the lower levels of the building, these are called lightwells. The pre cast concrete panels in this image make up the stair and liftwells. CONCRETE PROPERTIES The concrete panels of this building reduce in thickness at the higher levels from 200 on the ground floor to 150 (mm), this is to reduce the buildings overall load on the lower levels of the building. The slabs making up each level vary between 200 or 250 mm thick in areas requiring grater load bearing capacity. In this building, 95% of concrete is pre-cast and only 5% is in situ consisting of slabs and some columns and beams.
Figures 71-74. Off Site: Concrete Structure
WEEK 9 “OFF SITE� ROOF SYSTEM continued... As a flat roof, contact with water occur and the concrete of the roof slab has been specially treated by the addition of crystals that increase reduce the permeability of the concrete by repelling the water. What must also be noted is that when these in situ concrete slabs are made a massive amount of formwork is required that acts as a supporting mould for the slab, this is a lengthy process in comparison to the craning of pre cast concrete onto site. SERVICES Being a residential building this building requires obvious services including gas, water etc. This image to the left shows the gas piping in the Yellow, the hot water as the red pipe and the black pipe is the cold water. There is also a sprinkler system in place in the case of a fire, this is the thick dark red pipe. These pipes run through the ceilings and walls behind the plaster.
INTERNAL ENCLOSURE SYSTEM Internally the non-loadbearing wall sysem consistes of lightweight steel framing (as visible in the light green/ yellow). Upon these steel framed walls will go plaster board to enclose the wall system. Inside the walls will be adequate insulation and also the pipes and wires of services such as water, gas and electricity.
INTERNAL FRAMING continued.. Some parts of the internal steel framing system may actually have to bear the weight of windows, and due to the lightweight, malleable nature of the steel framing, slightly stronger timber studs may be used to ensure the load of the window will be adequately supported.
Figures 75-78. Off Site: Steel Framing
WEEK 9 “OFF SITE” OPENINGS Where openings such as windows exist, there much be framing wait adequate water proofing. A combination of water proof flashing and silicon may be used beneach the aluminium water frame that are generally very effective at preventing the entry of water into the building. Openings such as windows are the parts of the building where most heat is transmitted so not only do these windows need to be water-tight, but they also need to be able to minimise the movement of heat in or out of the building to reduce the need for artificial heaters or coolers that expend large amounts of energy.
CHALLENGES OF CONSTRUCTION One of the biggest challenges that construction of this building faced was the innacessibility of the site itself, due a combination of the close proximity neighbouring buildings and power lines as well as the fact that it is on a one way street access of cranes and machinery was a logistical nightmare. What they ended up doing was having to embloy a 30 meter tower crane that would lift each of the pre cast concrete panels over the neighbouring buildings and clear of the powerlines. This was obviously not ideal as extra safety precautions are required to avoid any damage to neighbouring properties. It also tested the patients of many neighbours who’s lives may have felt ‘put on hold’ during the construction of this building.
Figures 79,80. Off Site: Challenges of Construction
WEEK 10 When things go wrong... LATERAL SUPORTS AGAINST WIND & EARTHQUAKES
MATERIALS QUALITIES
COMPOSITE MATERIALS
Figures 81-83. Week 10 E-Learning
WEEK 10 DETAIL CONTINUED.... Three Dimensional Version of Detail Section This image shows the rough cutting of bricks and also the steel window frame in an attempt to make the steel window frame fit within the window opening. The window frame didnt fit within the window opening so adjustments had to be made which have negatively effected the window frame’s finish. The adjustments to the window frame have resulted in subsequent damage to the steel framing of the wall lights. As it would be very difficult to replace nothing has been done as of yet, but with exposed steel rusting should occur so a layer of waterproofing paint should be applied.
Figures 84. 3D Version of Detail
Above, is a three dimensional version of the detail section that we did in Week 9, although the plans dont show this in 3D it is good to be able to visualise how the sections fit in to their context as it can be sometimes difficult to visualise.
The waterproofing treatment of this steel window frame has been ineffective as the drip spots underneath it have begun to rust, this could spread to more visible areas of the window frame.
Figures 85-89. Window Frame Failures
APPENDIX CONSTRUCTION WORKSHOP For our construction workshop we were given two lengths of pine and one sheet of plywood, using these, we were set the task of construction a bridge structure that would span 1 meter and withhold the greateast load possible. For our design we decided to do an arched bridge, similar to that of the Sydney Harbour, we hoped would be capable of withstanding quite large loads.
CONSTRUCTION OF BRIDGE
From the E-learning module and also from Chings’ book, we knew that the strength of our bridge was dependant on strong joints, we cut the wood into eequal segments and the cuts were at angles that would give our arch an appropriate curve.
We then used nails as dowels that we hoped would effectively join the two pieces together.
CONSTRUCTION.....
After the two main strucural archs were made we used the plywood to join them together. We soon realised that the dowel joints were not sufficient in keeping the pine wood pieces firmly fixed so we added small pieces of plywood to these joints (Figure 94). At this point we had run out of materials, and at this point we realised that we had forgotted a vital component of an arched brigde, we needed something to prevent the bridge from flattening under the load. For example something with good tensile properties could have spanned the bottom of the arch that would have naturally helped to prevent the bridge from being flattened, an example of this can be seen in Figure 98. An actual bridge would incorporate some kind of cabling, but for our model bridge we could have used the plywood as it performs well under tension. Figures 90-94. Arched Bridge Construction
APPENDIX CONSTRUCTION WORKSHOP WEIGHT TEST Under the weight bearing test our bridge structure unfortunately performed quite badly, and the reason for this was immediately apparent why. Our structure itself was not poorly joined, the problem with our structure was that it did not have reaction forces to prevent the bridge from flatening under the loading. Perhaps if the bridge had of been a complete archway that had of distributed the load more directly to the ground an adequate reaction force would have increased its load bearing capacity.
LOAD DIAGRAMS As the load diagrams suggests, if we had have included a material with good tensile properties the bridge structure would have been able to bear a greater load before collapsing. Another way to prevent the collapse of our bridge structure would have been to place the bridge in between cliff walls or two solid vertical structures that would have provided necessary reaction forces to compensate for the loading.
Figures 98,99. Arched Bridge Load Bearing Models Figures 95-97. Arched Bridge Load Bearing Capacity
APPENDIX CONSTRUCTION WORKSHOP Whilst our groups bridge performed very poorly some other groups used the given materials to advantage and produced strong bridges that could bear significant loads. GROUP 1 This bridge structure used two parallel pinewood lengths connected together by ply, it performed relatively well, however it could have performed better. This group made the mistake of cutting the plywood up into small squares before connecting the two pine lengths, it would have been more effective if they had of left the ply as one long element as then it’s tensile properties would have given the structure more stength as the timber started to flex, ply is used in this way in timber framed building as a form of bracing. The group also made the mistake of facing the ply upwards meaning that it was under compressive forces rather than tension.
GROUP 2 This bridge’s structure encorporated two parallel pieces of pine wood and relied heavily on the timber’s flexibility as there was nothing adding to the bridge’s strength as they were not given plywood. This group made an unfortunate error of putting the pine pieces next to each other rather than on top of each other. With the two pieces next to each other they may as well have only used one pine piece as the second piece barely influences the overall structures length, unless the pieces were placed on top of each other, in that case, the timber’s strength would have effectively been doubled.
GROUP 3 This group’s bridge performed the best, bearing the greatest load. It was an effective design as it stacked the pine on top of each other and also managed to use the ply wood in a way that would take advantage of its tensile properties. The only problem with their bridge structure was that the screws used to attach the pieces caused weak point which when under a significant enough load were the sources of the first cracks, which gradually spread. If they had more ply at their disposal that could have covered the entire side area to give it a greater tensile strenght and if screws were only used at points under minimal loads they could have avoided creating weak points. Figures 100-105. Other Bridge Load Bearing Tests
REFERENCES & FIGURES Ching, F 2008, Building Construction Illustrated 4th Edition, John Wiley & Sons, New Jersey.
Cox Architects & Planners 2012, Oval Pavillion Construction Drawings, Cox Architecture Pty Ltd (Figures 40,41) Wood & Grieve Engineers 2012, Structural Drawings of Oval Pavillion, Cox Architecture Pty Ltd (Figures 44,45) Newton C 2014, Constructing Environments Lecture Week 1, viewed on 6/3/2014 Wood, J 2013, Block Tower Photograph, Unpublished (Figure 7) Wylie, J 2014, Balsa Frame Photographs, Unpublished (Figures 10-17) Wylie, J 2014, Balsa Design Sketches, Unpublished (Figures 8-9) Wylie, J 2014, Block Stacking Ideas, Unpublished (Figures 1-3) Wylie, J 2014, Cylinder Load Sketches, Unpublished (Figures 4,5) Wylie, J 2014, Load of Brick Layers, Unpublished (Figure 6) Wylie, J 2014, E-Learning Mind Maps & Sketches, Unpublished (Figures 18-24, 35-39, 42, 43, 50-52, 57-65, 68-70, 81-83) Wylie, J 2014, Melbourne University Construction Tour Photographs, Unpublished (Figures 25-34) Wylie, J 2014, Canopy Structural Models, Unpublished (Figures 46-50) Wylie, J 2014, Detail Section Sketch: Window Frame, Unpublished (Figure 66) Wylie, J 2014, 3D Version of Window Frame Detail, Unpublished (Figure 84) Wylie, J 2014. Off Site: Concrete Structure, Unpublished (71-74) Wylie, J 2014. Off Site: Steel Framing, Unpublished (75-78) Wylie, J 2014. Off Site: Challenges of Construction, Unpublished (79,80)
Wylie, J 2014, Window Frame Failures, Unpublished (Figures 85-89) Wylie, J 2014, Arched Bridge Construction, Unpublished (Figures 90-94) Wylie, J 2014, Arched Bridge Load Bearing Capacity, Unpublished (Figures 95-97) Wylie, J 2014, Arched Bridge Load Bearing Models, Unpublished (Figures 98,99) Wylie, J 2014, Other Bridge Load Bearing Tests, Unpublished (Figures 100-105.)